Artificial plank



@am ai? E928. LSgBS W. DROEGE ARTIFICIAL PLANK Filed July 25, 1925 INIENTOR.

W ,Droege @am m. M@

Patented Oct. 16, 1928.

UNITED STATES PATENT oie-Fica.

WILLIAM n. morera, 0

F FORT WAYNE, INDIANA.

ARTIFICIAL YLANK.

Application mea ruiy 28, 1925.

The invention adapted primarily highways.

relates to artificial planks for railroad crossings at The object of theinvention is to provide a plank which may be ma de and laid at a minimumof cost and which will form a highly efficient crossing material of longlife.

The invention' consists in a Vplank formed ot selected materials in suchmanner that each plankfts into and supports another.

I have found that a plank formed of bltucast e or

fated USB bitumen and 4in forming the plank I mix together 16 to 25% ofsilica dust or limestone dust and 54 to 71% of a graded sand, gravel,stone or quartz and 5 to 1Q% of powdered steel or to a temperature ofnot less than 325 F enheit and while 8 to 11F/fl of the bitumen,

iron and heat the mixture ahrthe mixture 1s hot I insert thoroughlymixing it with the aggregate to coat each particle thereof. The mixtureis then inserted.

into

a mold, a suitable reinforcing member 1s 1nserted into the mass andapressure of proximatcly 1500 pounds then applied to compress it toassume the shape of It is desirable that the a specific gravity of notythe mold.

per square inch 1s the mass and cause bitumen shall have less than 1.02;

that the silica or limestone shall be not larger than such as will passthrough a 200 mesh screen and the gravel, stone or quartz should be ofsuch size as to composition after compression.

'lhe milverized steel or iron lessens possibility of the liner materialsloosening bei wcen the grains of silica, or limestone form an almostvoidless the dust

or the particles of gravel, stoneor quartz, and it materially increasesthe resistance of the plank to trailic and shock.

When the compressed mass is 'from the mold and has cooled it has the fof the mold and when laid'at a grade eros removed a surface is presentedwhich resists wear by the traiic. No spiking of the sary and it is easyIn the' drawings View of the finished view of the plank; cross-sectionon line a transverse cross-section on plank to to layuand take up.

plank Fig, 3 a 3-3 of Fig.

line

The plank is also fire proof.

the' ties is neces- Figure 1 is a perspective Fig.2 a plan longitudinal2; Figa Serial No. 815,641.

is provided with an end rib 2 and a groove 3 at its opposite end forinterlocking endwise with other similar planks. A r1b t is formed on oneside of the plank and a groove 5 is formed in the opposite side. Thereinforcement comprises a rod 6 from'the op-` posite sides of whichproject the lugs 7 -This reinforcement extends substantially from end toend of the plank and the lugs thereof project toward the opposite' sidesof the plank preferably at an angle to the longitudinal axis of the rod.The reinforcement therefore reinforces the central portion of the plankand causes the same to have a vmaximum of strengthand rigidit The ribson one plank fit into t e grooves of other planks so that when a numberof these planks arelaid ata railway crossing they are interlocked andwill remain in position. Their weight is sufiicient to hold them inplace but they may be secured in place in any suitable manner when itis'desirable to do so. The side ribs on the planks adjacent one rail 8of the track may project under the tread 'of the rail and therebyfurther lock the planks inl place and this without interfering with thetravel of the Vehicle wheels on the rail., The planks adjacent theopposite rails 9 of the track could be made with ribs 5f* on theiropposite sides so t the planks may be interlocked with their neighborsand with the rails.

The plank may be used for various purposes, hence it is not limited inits use at grade crossings. The interlocking elements may also be ofvarious forms, trated beingl one such only.

In the claim I shall use the term gravel intending thereby to includesand, stone and quartz, since finely divided gravel is in reality sand.

What I claim is:

A plank composed of a mixture of 8 to 11% of bitumen, 16 to 25% of stonedust, 54 to 71% of inely divided gravel and 5 to 10% of powdered iron.

In witness whereof `I have hereunto setmy hand this 21st day of July,1925.

hatl

the form illus-

